Properly unwind the js stack for generated code

Surround all calls into generated code with a
try {} catch {} statement that resets the jstack
to the correct position.

Like this we properly unwind the js stack in all cases, and
can also use stricter assertions in our ScopedCallData, etc.
classes to check that the stack is healthy.

Change-Id: I7ca03e06ea55007be683305d9c2a6898cf5fc689
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/qml/jsruntime/qv4function_p.h b/src/qml/jsruntime/qv4function_p.h
index 595955a8ec..e9640fd925 100644
--- a/src/qml/jsruntime/qv4function_p.h
+++ b/src/qml/jsruntime/qv4function_p.h
@@ -50,6 +50,7 @@
 #include <config.h>
 #include "qv4value_def_p.h"
 #include <private/qv4compileddata_p.h>
+#include <private/qv4engine_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -85,7 +86,17 @@ struct Function {
 
     const CompiledData::Function *compiledFunction;
     CompiledData::CompilationUnit *compilationUnit;
-    Value (*code)(ExecutionContext *, const uchar *);
+    inline Value code(ExecutionContext *ctx, const uchar *data) {
+        Value *stack = ctx->engine->jsStackTop;
+        try {
+            return codePtr(ctx, data);
+        } catch (...) {
+            ctx->engine->jsStackTop = stack;
+            throw;
+        }
+    }
+
+    Value (*codePtr)(ExecutionContext *, const uchar *);
     const uchar *codeData;
     quint32 codeSize;